In the field of image sensors, because of factors such as manufacturing tolerances, impurities and environmental conditions that might lead to irregularities in parts of the sensor, the image sensor might not produce a uniform output signal, even when subjected to a uniform stimulus.
To compensate for non-uniformities, a manual calibration of the image sensor is sometimes performed. In this calibration process, corrective parameters such as bias and scale factor are derived. In use during image capture, the corrective parameters are applied to raw output from the image sensor, so as to obtain corrected output signals in which non-uniformities are reduced.